Robert Nkemdiche 911 -- 'Seemed Delirious, Incoherent' ... After Hotel Fall

Ole Miss defensive lineman Robert Nkemdiche was bleeding -- and appeared delirious -- after falling out of an Atlanta hotel window this weekend ... so says the person who called 911.

On the recording, obtained by TMZ Sports, the witness says she was at the valet at the hotel when she noticed an emergency situation ... and then saw Robert.

The woman tells the operator she didn't see Nkemdiche fall -- but saw that he was in bad shape and in need of immediate medical assistance.

He was moving and breathing -- however, the woman says, "He didn't seem coherent, he seemed like he was delirious."

The woman also told the 911 operator the situation was so dire -- that people on the scene were requesting a defibrillator.